Slipper type bearing structure



\ June 22, 1954 w, E, BRlLL 2,681,838

SLIPPER TYPE BEARING STRUCTURE Filed July 2, 1949 maentor @WWW l Gitomegs Patented June 22, 1954 SLIPPER TYPE BEARING STRUCTURE William E. Brill, Cleveland, Ohio, assignor to General Motors Corporation, Detroit, Mich., a

corporation of Delaware Application July 2, 1949, Serial No. 102,738 7 Claims. (Cl. 308-240) The present invention generally relates to bearings and more particularly to slipper type bearings of arcuate form.

1n that slipper type connecting rod bearings bear` only on an arcuate portion of a crankpin the bearing loads thereon are high and the bearing surface of the rod is usually provided with bearing alloy bonded directly to the surface to provide satisfactory heat transfer and load distribution betweenthe alloy and rod bearing surfaces toprevent separation of the alloy by fusion` of thealloyland/or impact loads imposed thereon. :The bonding of the bearing alloy to the rod involves a long and expensive process in order toprovide satisfactory bearing operation for long periods of time.

, The object of the present invention is to provide suitably formed bearing surfaces on a connecting rod and lubricating and coolingoil passages communicating therewith for retaining a replaceable bearing insert in firm and uniform metal to metal contact with the rod bearing sur- 4faces and adjacent the rod. lubricating and cooling `passages to insure equal load distribution and V'adequate cooling and lubrication of the bearing surfaces of the rod and bearing insert which may be readily replaced.

The slipper bearing structure by which the above object is accomplished will become apparent by reference to the following detailed description and drawings illustrating the novel features of the invention.

.Y Figure 1 of the drawings is an end elevational view of the bearing structure in disassembled 4relation with parts broken away.

Y Figure 2 is a View similar to Figure 1 with the bearing structure assembled and parts broken away.

Figure 3 is a cross sectional side elevational view taken on line 3-3 of Figure 2 with parts 'shown in section and broken away.

" vFigure 4 is an enlarged View of a portion of Figure 3 withV parts shown broken away and in section.

Figure 5 is an enlarged view of a portion of Figure-2 with parts shown broken away.

`As best shown in Figure l a connecting rod I is shown provided with an arcuate slipper type bearing portion, generally indicated by the char- 'act'erreference 3,comprising opposite end thrust faces 4 and side surfaces 5. As best illustrated in Figure 2 the side surfaces project radially, as shown by projection lines w--b which intersect the longitudinal center plane `of the rod, indicated by the line c, at the axis of curvature d of thefarcuate surfaces of the bearing portion 3 of ing groove l.

the rod I. An arcuate bearing groove, generally indicated by the character reference II, is provided in the arcuate outer end face of the rod bearing portion. This bearing groove 'i has an arcuate bottom surface 9 coaxial with the arcuate surfaces of the bearing portion 3 and side Walls converging outwardly from the bottom surface 9 at an angle greater than the converging radial sides 5 of the bearing portion. The projection lines e-f from the sides II of the bearing groove I intersect the radial center plane of the coaxial arcuate surface 9 of the bearing groove 'l on a line g parallel to the axis of curvature of the surface 9 and between this axis and the surface 9 as best illustrated in Figure 2. p

As best illustrated in Figures 1, 2 and 5, clearance slots I3 are provided at the junction of the sides I I with the bottom surface 9 of the bearing groove 'l and, as illustrated in Figures 1 to 4 arcuate oil cooling and lubricating grooves I5 extending inwardly from the end faces 4 into the central end portions of the bottom 9 of the bear- As shown in Figure 3 drilled oil passages I'I-IS extend inwardly and upwardly from the `end surfaces ofthe oil grooves I5 and intersect a longitudinally drilled oil hole 2I in the connecting rod adjacent the end of the hole `2I spaced radially outwardly from the bottom surface 9 of the bearing slot 1. The drilled passages I`II9-2I serve to convey cooling and lubricating oil to the opposite end piston pin -bearingof the rod, piston and engine cylinder wall, not shown, from oil grooves I5 which are supplied with cil pressure from a passage in the .engine crankshaft through radial holes inthe ends of the crankpin, not shown, which intermittently register with the oil grooves I5 of the connecting rod I.

A metallic arcuate bearing insert, generally indicated by the character reference 23 in the various iigures of the drawings, of similar arcuate form to that of the connecting rod bearing groove I and having similarly converging sides and of slightly larger arcuate length and slightly greater radial thickness than the depth of the bearing groove 'I is provided to permit longitudinal insertion of this bearing insert into the groove upon expansion of the rod by heating and/or contraction of the insert by cooling. The diierence in dimensions of the insert 23 and rod groove 'I are such that the bearing portion 3 of the connecting rod and the bearing insert 23 is retained in a stressed condition in the groove at substantially the same temperature under` all operating conditions of the engine and uniform equal and opposite forces are `applied. between the opposite groove and bearing insert thereby retaining the sides and inner arcuate surface of they insert in firm and uniform metallic contact with the sides l! and bottom arcuate surface-9 of the bearing groove 'l of the rod I so thatth'e bearin'g'loadsare distributed uniformly and ecient heat transfer is obtained between the bearinginsert. and bear ing portion of the connecting rod. A suitable Y bearing alloy 25 is readily bonded to the" outer surface of the bearing insert and slots 2l are shown in the end surface of the insert to provide thin wall portions at the ends overhanging the outwardly facing walls ofthe oil grooves l5 in ther rod bearing portion as best illustrated in Figures Sand 4. These thin wall portions'of the insert are peened over into longitudinal abutting relation with the outer facing surfaces of the oil groovesl te position the ends of the insert for adequate lubrication and cooling of the insert and end thrust faces ofthe rod and permit-free exit of the coolingY and lubricating oil through the drilled passages I'T-l-Z'l inthe rod i.

The rod'and-insert are accordingly maintained atV substantially the' same'temperature under all operating conditions of the engine to retain uniformdistribution and eflicient heat transfer therebetween. It will be evident that the bearing insert may be readily removed from the bearing groove by cutting an axial slot therethrough for insertionl of another insert. The insert cannot moveflongitudinallyin the slot to block oil flow to either of thedrilled-passages l1'|9fby reason of the end portions 29V ofv the insert which are peene'dv into abutting vrelation with the surfaces of the oil grooves I5 provided in the-connecting rod bearing portion 3.

I claim: y

l. In a slipper typebearing structure, a connectingrodv including an endbearing portion having end thrust faces, a bearing slot extending axially'between the end-thrustV faces and including an arcuate bottom' face and radially inwardly inclined sides, saidV end thrust faces having oil lubricating and4 cooling slots inclined inwardly into the bottom'of thebearing slot adjacent the ends and a bearing insert of arcuate formhaving inclined sides in firm`- abutting contact with the sides of the slot to stress the insert and hold one arcuate face in uniform contact with the bottom of the1slot, said4 insert 'having end'portions projecting axially part way intothe oil lubricatinggrooves inthe end thrust faces of the connecting rod bearing portion to retain the ends of the insert within'the end thrust surfaces of the connecting rod. Y

2. In a slippertypeb'earing structuraan insert supporting member having anV arcuate section grooveV extending longitudinally of the' bearing axis. and terminating circumferentially of said axis in sidewalls converging toward each other along lines intersecting. each other between said axis and said groove, and a-concentric arcuate shaped .bearing insert' seated in said groove and having its circumferentially spaced., sides forming a. shrink fit withsaid groove side walls'.`

3; In a slipper type bearing structure, an arcuate shaped bearing insert terminating in circumferentially spaced sides converging toward each other along lines intersecting the radial midplane of the structure intermediate the bearing axis and the intersection of said plane with the Y insert, and a supporting member therefor having a groove with anlarcuate'bottom surface-concentric with said insert and terminating'inv circumferentially spaced side walls having a shrink fit with said insert sides whereby said insert and said bottom surface: are held in clamped relation with each other.

4. The inventionV defined in claim 3, wherein said member is provided with end thrust facesat the axially opposite ends of said groove, said thrust'.` faces` having lubricant receiving grooves extending., circumferentially of the bearing axis and intersecting said bottom surface, said insert having its axially opposite ends in locked engagement with said lubricant receiving grooves.

5; In aslipper type` bearing structure, a'v connecting rod having an end portion having abears ing axis extending transversely to-the'longitudinal axis of the rod, saidV end portion having radially converging sides in circumferentially spaced relation about said bearing axis, end thrust faces inlongitudinally spaced relation along said bearing axis and a bearing groove ofA arcuate section concentric with said bearing axis, said bearing groove terminating longitudinally of said bearing axis at saidthrust faces and-terminating circumferentially of said' bearing axis side walls spaced from said' radially converging sides, said side walls converging toward each otherat an angle greater than the angle included by'said radially converging sides, said end thrust faces having lubricant receiving grooves extending'circumferentiallyV ofv saidjbearing axis and intersecting said bearing groove, and an arcuate secf tion'bearing insertseated in said bearinggroove and havinga bearing surface concentricwith said bearing axis; said insert having its circumferential extremities forming a shrink lt with said bearing groove side walls and its longitudinal extremities in locked engagementwith said'A lubricant receiving grooves. Y

6. The invention defined in claim 5wherein saidrod is providedwitha longitudinal axial pas'- sage forV lubricant and a connecting lubricant passage leading toV thev lower end of said axial" passage from each said lubricant groove'.

7. The method of securingja bearing insert to a slipper type supportingmember comprising'the steps of forminganarcuate section grooveV inthe face of the member concentric with the bearing axis, forming theY circumferentially opposingside walls of said groove in converging relation'along linesA intersecting. the radial mid-planel of said member between the bearingjaxis and'` said face,

forming the bearing, insertrto an arcuate shape section concentric withthebearing axis and'to an arcuate length slightly greater than the circumferentialV spacing` of said side walls,v thermally expanding. and contractingl the supporting. member and` insertrespectively,.to permit insertion Y of theinsert into said groove, andthen allowing said member'and insert to. return to their'original temperaturesV while the insert? remains. in said groove.`

References Cited in. the filesof thisipatent;

Urn'rn'nl sfrArEs-l enfin-Nrs v NumberV Name, Datey A,

1,121,849 Kraiund'. Dec. 22; 1914 

